The primary goal of this proposal is to improve the safety, health outcomes, and cost-effectiveness of hospitalizations of persons living with HIV (PLWH) in the U.S. Up to 20% of hospitalizations of PLWH are complicated by clinically-significant medication errors. In addition to toxic effects, these errors may result in HIV viral breakthrough, and patients can develop medication resistance, thereby reducing future treatment options. Our preliminary data indicate most errors could be prevented through medication review performed by an HIV-experienced nurse and an HIV-trained clinical pharmacist. We hypothesize that such reviews may also be successful in preventing Hepatitis C (HCV) medication errors. Over a third of PLWH in our hospital are co- infected with HCV. In coming years, up to a million HCV-infected Americans may begin HCV treatment courses. The consequences of HCV medication errors will be similar to those seen in HIV and include HCV viral breakthrough. HCV breakthrough carries an enhanced concern for cost of care because when it occurs, the HCV treatment course must be restarted, increasing overall HCV treatment cost by up to $100,000 or more. Hospitalizations of PLWH also represent critical opportunities to promote engagement (follow-up) of PLWH in outpatient HIV care. Currently, a quarter of PLWH have never linked to (had a first visit with) an HIV provider. A third of those who have linked to care later become lost to follow-up. Consistent engagement in outpatient care enables PLWH to realize the transformative effects of HIV therapy. Medical therapy changes HIV from a terminal condition to a chronic comorbidity with a normal lifespan. Also, HIV viral suppression through medication use reduces HIV transmission by over 95%. Widespread and consistently-used HIV therapy is thus capable of greatly reducing the HIV epidemic. Unfortunately only a third of US PLWH have consistent HIV viral suppression. Improving linkage and reengagement are leading national HIV goals. The overall hypotheses for this study are that a hospital HIV/HCV Support Team (HST), consisting of nurse supported by a clinical pharmacist, can greatly reduce HIV and HCV medication errors and improve post- discharge linkage and reengagement into HIV care of PLWH. The HST intervention may be widely disseminated to other hospitals, and the HST intervention may be highly cost-effective because of reducing HIV transmission and the incidence of opportunistic infections. The specific aims are: 1) Implement an HST as a quality improvement intervention at Johns Hopkins Hospital in Baltimore, MD. Using a phased, cluster- randomized roll-out (stepped-wedge study), assesses whether the HST decreases HIV and HCV medication errors and improves HIV linkage and reengagement in care. 2) Develop a toolkit for non-HIV/HCV expert nurses and clinical pharmacists to learn and perform the HST roles and an implementation strategy for hospitals, and 3) Use the Cost-Effectiveness of Preventing AIDS Complications model to project the HIV- related clinical outcomes, costs, and cost-effectiveness of the HST intervention.